Metajxpiercing



HARRY R. GEER, or JOHNSTOWN, rnnnsytvama.

' METAL-PIERCING.

1 Specification of Letters Patent. 1 Patented 1 1 1919 'Application filed June 21, 1918. Serial No. 241,304,

' To all whom it may concern Be it known'that I, HAR'RY- R. GEER, a citizen of the United States, residing in the city of Johnstown, in the county of Cambria and State of Pennsylvania, whose post-oflice address is I J ohnstown, Pennsylvania, have invented certain new and useful Improvements in Metal-Piercing; and I do hereby declare the following to be a full, clear, and

exact description, such as will enable others 7 skilled in the art to which it appertains to make and use the same.

My invention relates to method and apparatus for piercing metals with particular reference to producing tubes, hollow articles,

shells, etc. In order to simplify the de-.

scription, I will confine the same herein to producing shells.

The operation of my invention, briefly and generally stated, consists in taking a blank of metal, preferably heated, and which may be solid, cylindrical or of any othersuitable form, placing the same in a casingjor bushing, which is adapted to surround and support it on its sides, the bushing being closed at one end by a fixed block with its end or shape conforming to the finished shape of. the product, whi the bushmg which immediately surrounds the sides of the blank, has a temporary bottom sup port and is so held in the casing so as to be free to move lon itudinally therein. After the blank is p aced within the bushing with one end against the fixed block, a

piercing plunger is projected against the other end and into it and causes a depresslon or opening within the blank and the displacement or plastic flow of the'side portaons of the metal blank is, in part, opposite to the movement of the piercing tool.

of the metal of the blank which is adjacent 1 to it. Whennsing the previous method of cupping or piercing shell blanks or similar forgings wlthin a cylindrical or other shaped bushing provided with a solid or Sta tionary bottom, this of necessity-produces an upward flow of metal under hi h pressure between the piercing bar and t 1e inner Walls of the bushing, thereby causing a severe cutting or abrasive action of the flowing metal, making it practically impossible to provide a bushing which will withstand this severe use, all of whichis obviated by 'my invention, in which, the bushing is allowed to travel with the flow of the metal being operated upon. a 1 v .I have discovered by actual trialsthat in using stationary bushings, there is a,- very excessive pull due tothe attempted movement of the bushing and its container, which is of such extent'that it has broken'holddown bolts which are able to Withstand a tensional stress of 600,000 pounds, the

pressure on the piercing plunger being about 1,400,000 pounds. In other words, the downward pressure of 700- tons on the piercing bar, causes an uplift of about 300 tons on the bushing, when it is attempted to-hold the same stationary, as customary; By the use of my method and movable bushing, a pressure of only 400 tons is required on 'the piercing 'bar, owing to the fact-"that thefriction is reduced, due to the arrangement of the bushing which 'is movable' wlth the flow of metal, thus reducing all the strain on the hold-down bolts and'allowing theoperation to be performed with almostzha lf the pressure and expense, and ofcourse the tool may be of much lighter *andf'cheaper construction.

Having thus given a general descr ptlon of my invention, I will 'now, in order to make I the matter more clear, refer to the annexed sheet of drawings forming part of thisspecific'ation and in which like charactersrefer to like parts.

Figure 1 is a vertical'cross sectlonalelevation of my ap'paratusw'ith the-pierc ng tool in its upper position andthe bushing in its lower position, ready to begin operation upon the blank;

F'g. 2 is a cross sectional elevationof the v same apparatus with the pierciilg tool in its lower position and the bushing in its upper position, after the forging is completed.

Referring now to the characters of reference on the drawings: v 1 is the base of the apparatus, 2 an oute casing which may be hollow cylindrical, or of other form, provided with the hold-down base flanges 3 and the hold-down bolts the opening within said casing being indicated as 5. A'ledge or supporting surface 6 is provided at the upper part of the casing to receive the upper flange of the centering ring 26, which ring is adapted to be placed in position,. as shown, or removed as desired, byany suitable means. This centering ring is provided with an opening concentric with the bore of the shell or tube, and is adapted to guide the piercing tool concentrically so that the work may be exact. Recesses 7 are provided in the upper portion of the casing 2, to allow the introduction of a forked tool, not shown, for the purpose of stripping the forging from the piercing bar in case they should adhere to each other. 8 is a tubular container adapted to fit within the casing 2, provided with water-circulating grooves-9', connected with the water .inlet pipe 10 at one endand the water-outlet pipe -11 at the other end, these grooves being preferably 'made helical and continuous so that the water passes around the outside of the bushing 14, for the purpose of keeping it cool and lengtheningits life.

An opening 15 is provided inthe base 1,-

through which extends a plunger 16 which is adapted to be operated by any suitable means not shown, for the purpose of pushing out or extracting the finished forging.

-18 is a base block adapted to contact with r and support the bushing 14 when in its lowered position. A bottom block or die 21 is arranged with its upper portion project-- ing within'the die block 14, as illustrated,

, and having a lower portion 20, adapted to be normally seated upon the base, as shown. The upper portion of the die block 21 may be made of any suitable form to correspond with that of the end of the forging. The blank, before piercing, is 23, the piercing bar 24, the blankor forging after being pierced is 25. p

The operation of my apparatus is as follows :The piercing .bar being withdrawn, the centering ring is also withdrawn, the blank 23, which is previously heated, is dropped within the bushing 14, the centering rin trated, t e piercing bar brought down with great force and penetrates within the blank,

I as illustrated in Fig. 2. It will be seen that the finished forging 25 is much longer than the blank and that the metal as it extrudesbackwardly between the piercing barand the die-must flow upwardly and carries with it the bushing 14 and attached parts which are free to move backward] but which cannot move forward at the eginning of the operation on account of the fixed support on which the forward end of the is replaced inposition, as illus-- blank initially rests. After this is accomplished, the piercing bar and centering ring are withdrawn, the extractor 16 is pushed upwardly, which loosens theforging from the bushing and the forging is then lifted out by any suitable means.

Although I have described and illustrated my invention in considerable detail, I do not wish to be limited to the exact and specific details thereof as shown and described but may use such modifications in, substitutions for, or equivalents thereof, as are embraced within the scope of my invention, or as pointed out in the claims.

Having thus described my invention, what I claim and desire'to secure by Letters Patent is 1. The method of metal piercing which consists in placing a substantially cylindrical or prismatic blank in an inclosing solid die or bushing,.which die is initially supported at one end, then projecting a pierclng bar against and into said blank Whileallowi-ng said bushing to move backwardly withthe extrusion flow of the metal adjacent thereto while cooling means are applied to at one end, the sides of said bushing being adapted to contact with the sides of the blank,

one end of saidblank being firmly supported, then projecting a .piercing bar against and into the other end of said blank while allowingv the bushing to travel back-' wardly with the extrusion flow of the metal of the blank adjacent thereto, while cooling ,means are applied to said bushing,

3. A metal piercing apparatus, comprising a solid bushing or die adapted to surround the sides of a blank, provided with a support at one end, the bushing being held within a container adapted to fit around the exterior thereof and provided with cooling means, a piercing bar adapted to be projected into the other end of the blank and means for guiding said bushing and attached container while allowing them to move backwardly with the extrusion flow of the blank.

4. In a metal piercing apparatus, a guide casing, a tubular container, provided with a bushing, slidably mounted therein, fluid cooling "means for said bushing, a fixed suport for one end of the bushing, and apiercmg bar adapted to be projected into said bushing and withdrawn therefrom.

In witness whereof I hereunto afiix my signature.

. HARRY R. GEEK. 

